Forthe non-biologists out there, every cell in your body, or your cat's, or even the planaria lurking in the pond, share the same kind of cell membrane. This is comprised of a bilayer of phospolipids, with the hydrophobic ends sandwiched in the middle of the bilayer, and the hydrophilic sides presented to both the cell interior and exterior. Floating in this fluid, lipid membrane are lots of different proteins; some exposed on either side, others may protrude into the extracellular space, others intracellularly. They have a vast range of functions, from cell surface antigens and adhesion molecules to receptors for drugs and hormones, ion channels, transporters or gap junctions.

Understanding what happens on either side of the membrane is not that hard in the scheme of things. Water soluble proteins, such as those found in the cytosol or released extracellularly are much easier to characterise than their membrane bound relations. Visualising the structures was limited by the technology available, whereby proteins have to be purified and then crystalised for X-ray analysis. This works OK for free floating proteins, but the process tends to destroy the structure of the membrane bound region. Right now you're probably asking why you should even care, but these membrane proteins are involved in diseases such as atherosclerosis, where transporter proteins traffic cholesterol into or out of cells. Being able to accurately understand the structure and mechanism of action of these proteins would greatly aid the development of new therapies.

New advances are allowing membrane biologists to catch up. Higher resolution imaging allows structures to be determined from smaller amounts of the target protein, and advances in overexpression have made it easier to get enough to actually stick under the 'scope, but what really struck a bell with me when reading the accompanying editorial* was this statement:

These challenges in expression, coupled with the difficulty in obtaining diffraction-quality crystals, mean that there is no guarantee of success. It can take several years, in many cases longer than the standard three-year postdoctoral contract, so embarking on such a quest is a risky business.

The changing nature of how academic science is conducted in the US and abroad, with lots of postdocs on short term contracts will surely have an effect on the kinds of studies that are carried out. Are lengthy projects that could potentially have wide-ranging benefits simply not being carried out because of fears over job security and the increasingly temporary employment nature here in the Ivory Tower? It's no secret that the postdoc system in the US is need of fixing, and steps are being taken to work towards that end. I can't help sometimes looking back at my predecessors in the 1950s and 1960s with envy though.